The UKs most senior judge has expressed shock at the gender pay gap in her own profession.

Baroness Brenda Hale of Richmond responded to figures published on the government’s gender pay disparity website while delivering a public lecture marking 100 years of female suffrage.

Women are paid nearly 40 per cent less than men at Linklaters, the first of the large revenue London law firms – or magic circle firms – to report its gender pay gap, also revealing that female employees receive nearly 60 per cent less than men in bonuses.

“It shocks me and I don’t have an easy answer,” said Hale at the annual Pankhurst Lecture on 9 February at Manchester University, where she taught in 1966-1984. She added that women need to ask for better pay.

“A lot used to depend on whether you asked and what people believed they could keep you with. Women are prepared to stay – mobility is a serious problem for a lot of female employees. One of the reasons is thought to be not being able to move to where the more senior posts are.”

Hale is an outspoken champion of diversity and spoke candidly about gender equality during the event in honour of Women’s Social and Political Union (WSPU) co-founder Christabel Pankhurst, a Manchester University alumnus. Pankhurst received a first-class law degree but was not allowed to practise the profession because she was a woman.

Hale said that as a judge she had “mixed feelings” about her suffrage activities.

“There is a view that the WSPU’s increasingly militant tactics set back rather than advanced the cause for women’s suffrage and any judge must have reservations about the deliberate law breaking and political strategy. But their courage and self sacrifice cannot be doubted.”

Last year the West Yorkshire-born judge became the first woman to be appointed president of the Supreme Court – the latest in a trailblazing career of firsts. She was the first woman, and the youngest person ever, to be appointed to the Law Commission, overseeing a number of important reforms to family law. In 2004 she became the first appointed female Law Lord before becoming the Supreme Court’s first female justice and its first deputy president before her appointment last year.

“When I joined the Northern Circuit in 1969 women were still not members of the barristers’ mess.”

Reflecting on Pankhurst’s application for admission to the Bar in 1904, Hale says the law’s “loss was female suffrage’s gain” and referred to archive evidence showing that one reason for refusing her was that “qualifying for the Bar involved eating a great many dinners”.

“It was thought unseemly that men and women should take their meals together,” Hale said.

That attitude prevailed long after women were allowed to become barristers. “When I joined the Northern Circuit in 1969 women were still not members of the barristers’ mess and we could only dine with the other barristers on specially decorous ladies’ nights.

“There was passionate debate about whether we should become full members of the mess and attend on grand nights – when apparently the men behaved in ways their mothers would disapprove of.”

Hale acknowledged the parallels with the Presidents Club Gala, attended by some law professionals, which caused outrage last month when it was revealed to be an open forum for sexual harassment and sexism.

She said men-only clubs are bad for professional women because of the nepotism they promote among male colleagues and does not believe that judges, who should be “champions of equality”, ought to be members of them.

“I am fairly sure they wouldn’t go to a white-only club, or a straight -only club, but for some reason they think they can go to a club for men,” she said.

Hale pointed out that 2018 doesn’t just mark 100 years of some women gaining the vote – those over 30 or who owned land – but 100 years of female MPs, 90 years of women being able to vote on equal terms as men, and 60 years of women in the House of Lords. Next year, however, she said, marks an arguably more important anniversary for women – 100 years of the Sex Disqualification (Removal) Act, which allowed women to participate in civil life and hold public office, as magistrates, jurors and in other professions. Marriage was no longer allowed as a bar to these roles.

She spoke of other female pioneers, including Margaret Mackworth, who campaigned to use her hereditary peerage and sit in the House of Lords, and a number of northern women in law including Rose Heilbron – the first woman to hold judicial office when she was appointed recorder of Burnley in 1935 – and Cheshire-born Elizabeth Lane, who became the first woman county court judge in 1962.

“That was the year before I went up to university to read law. It never occurred to me I would be any sort of judge. There weren’t any of them about.”

She added: “The north can feel pretty proud of itself. Things have evened out a bit – the others have caught up now.”

Hale also spoke of her own mother. “She was not prominent or famous but she exemplified the first generation of women to have the vote and the transition in their lifetimes from a presumption of dependence to the possibility of independence, a transition that could scarcely have happened without the vote. It is the 110th anniversary of her birth in 1908. I didn’t realise it at the time but what a great role model she was,” she said.

Considering how far women’s equality still has to go, Hale said she is “relieved” to see women are using their vote. “The only significant difference is that women are significantly more likely than men to cast their votes in seats where a woman MP was elected. Women are also far less interested in the campaign in seats where a man was elected, and much more likely to agree that government benefits people like me if they have a woman MP, ” said Hale, referring to an Electoral Commission study.

“The authors suggest that the election of women is important to encourage participation by women as citizens in democratic processes but there’s still large discrepancies in the numbers of women elected to Parliament.”

Just 30 per cent of MPs are female, but it’s a vast increase since the 1997 election, before which it was under 10 per cent.

Much of the leap in female MP numbers she ascribes to positive discrimination

“In 2016, for the first time there were more female MPs ever as there were male MPs then in the House of Commons,” she said with the same irony she used to point out that the 12-strong Supreme Court managed to double its number of female judges last year – from one to two. “It is something to celebrate but it’s also something to weep over.”

Much of the leap in female MP numbers she ascribes to positive discrimination. “This is a very rare example where positive discrimination is allowed by law and there are sophisticated arguments to permitting this exception to gender neutrality in a democracy where each member of the electorate should be entitled to equal representation.

“Otherwise it’s not generally allowed. Choosing a woman in preference to a man is only allowed where they are of equal merit.”

Hale believes she has benefited from unofficial positive discrimination at points of her career but says she doesn’t think it’s a tactic the law profession should adopt.

“I don’t myself think the answer does lie in positive discrimination because I think an open and transparent merit-based system is the best way for the candidates themselves, as well as the general public and the profession, to feel confident. Everyone should know they have been appointed on merit and not because they are a diversity statistic.”